Susceptibility of Populus deltoides Bartr. to Melampsora larici-populina and Melampsora allii-populina. I Qualitative Analysis of a 6x6 Factorial Mating Design

1993

S. 179-188

21 Lit. Ang.

Unselbständiges Werk

200051403

Qualitative susceptibility to Melampsora spp. was observed in a 6x6 Populus deltoides factorial mating. For each of the 3 inocula tested. Melampsora larici-populina races E1 and E2 and Melampsora allii-populina, segregations that occured in qualitative tests cannot be explained with less than 3 genes for susceptibility-resistance. Comparison with El Karkoury's results (1991) suggest that race E1 would have another virulence gene which is not present in E2. However, the observed segregation pattern cannot be explained without another gene common to E1 and E2. Within 3 full sib families, qualitative resistance to both Melampsora allii-populina and Melampsora larici-populina may be genetically linked. Obviously, several unidentified races of Melampsora allii populina were present in the nursery trial.